The rise in Earth’s temperature is making snow lines and glaciers recede on mountain ranges all over the world. While this is a worrying trend, it’s revealing hidden bits of history to archaeologists.

In Norway, the receding Lendbreen glacier at 6,560 feet above the sea level has revealed an ancient wool sweater dating to the Iron Age. Carbon dating has revealed that it’s 1,700 years old. It was made of sheep and lamb’s wool in a diamond twill, and was well-worn and patched from heavy use. The Norwegian research team estimates that the person who wore it would have been about 5 feet, 9 inches tall.

The results of the study have recently been published in the journal Antiquity.

This isn’t the first discovery thanks to receding glaciers. The most famous, of course, is the so-called “Iceman”, a well-preserved corpse of a man who died in the Alps around 3300 BC. Last year we reported the discovery of the bodies of soldiers from World War One in the Alps. in Norway, about 50 textile fragments have been recovered in recent years, although the sweater is the first complete garment.

Most discoveries have been accidental, with hikers and mountaineers reporting their finds to the appropriate authorities. In the Iceman’s case, people originally wondered if the well-preserved body might have been a recent murder victim!

So if you’re hiking near a melting glacier, keep an eye out for ancient artifacts and bodies, and remember that it’s illegal to pocket them. Do science a favor and call a park ranger.

I’m in a northern state of mind. Perhaps it’s the hail tickity-tacking off my window, or maybe it’s because Gadling is sending me to Estonia this February. That’s right, I’ll be freezing my butt off for your edification and entertainment.

Reading about the great Estonian castles such as Narva and Paide, I wondered which is the northernmost castle in the world. That great provider of facile and not always accurate information, the Internet, came up with several answers.

Called Olavinlinna in Finnish, construction started in 1475. At the time, the sparsely populated Savo region was in the hands of the Swedish crown but the Russians also wanted it. In fact, the Russians wanted it so badly that they attacked it several times, even before the castle was finished. The Russians finally took it in 1714 and kept it until the region became part of Finland when that nation became independent in 1917.

A castle this old always has its share of legends. The most persistent is the tale that a beautiful maiden was walled up in the castle as a punishment for treason. She must have been innocent because a rowan tree grew near the spot, with flowers as white as her virtue and berries as red as her blood. A nearby spring has a water sprite, and the castle was once saved by a giant black ram that made so much noise the invaders fled.

There’s a museum of Orthodox religious items on site and you can even hire out the castle in case you want to get married in the far north. The town of Savonlinna is a four-hour train ride from Helsinki and hosts an annual opera festival.

%Gallery-176848%If you aren’t a traditionalist and any old fort will do, the prize for northernmost castle goes to Vardøhus Fortress at 70° 22′ 20″N on a Norwegian island in the Barents Sea. There was a castle there as early as 1306 to control the fur and fish trade but nothing remains above ground today, so while it once may have been the northernmost castle in the world, it’s no longer standing and doesn’t count in my book.

Instead there’s a well-preserved star fort from 1738 that offers tours. Star forts came into prominence in the late 15th century as an adaptation to early cannons, which could knock down a castle wall before you could say, “We’re facing superior technology, run!” These forts had earthen embankments faced with stone and were laid out in the shape of a star to deflect cannonballs and provide crossfire.

Vardøhus Fortress proved vital to Norway’s interests yet never saw action until World War II. It’s still operating today and the five-man garrison has the duty of firing a cannon on national holidays and also when the full disk of the sun first appears over the horizon on January 21. This event is a holiday in northern Norway. You can find out more about Vardøhus along with plenty of photos over on The Lost Fort blog.

While no stretch of the imagination could make Thule Air Base in Greenland a castle, you have to tip your hats to the men and women of the United States Air Force and their NATO allies for living at 76° 31′ 52″ N. That’s 750 miles north of the Arctic Circle. It’s said to be the northernmost military base in the world. I suspect the Russians would disagree if they were willing to divulge that sort of information.

Snowkiting is becoming big in Norway. At first glance it looks like some extreme fun in harmony with nature. After all, you’re just zipping across the snow while being dragged by a kite. It looks environmentally friendly.

Not true, says a new scientific study. The BBC reports that Norwegian scientists have discovered the kites spook reindeer and may have a negative impact on their population.

The scientists studied the response of reindeer to skiers and snowkiters and found that the reindeer showed a much greater fright response to snowkiting. They theorize that it’s the swooping kite that scares the animals. Because the kite is visible from farther away than someone on skis, reindeer are running far away. This may limit their feeding and breeding grounds.

The study concludes that controls need to be put in place to ensure reindeer aren’t harmed by this new craze.

In the classic 1994 outdoor film “The River Wild,” Meryl Streep’s hapless husband manages to create a signal fire to let his kidnapped wife know that he is still alive and planning on staging a rescue effort. Upon seeing the wafting plumes of smoke emanating from the mountainside, this inevitably leads Streep to attempt to paddle a whitewater raft down “The Gauntlet” in an effort to kill Kevin Bacon. By the end of the day, Streep manages to beguile Bacon and thereby saves the life of her son and is reunited with her smoke-sign savvy husband.

This, of course, is the Hollywood version of signal fires.

Back here in reality, however, occasionally you break your foot while hiking on a remote Norwegian island, lie incapacitated in the woods for three days … and then you set the entire mountainside ablaze.

This was exactly the fortune of an unlucky hiker who recently fell and broke his foot while hiking alone on the Norwegian island of Hillesoy. In an article posted by Outside Online, a 25-year-old Canadian man attempted to ignite a signal fire in an effort to call for help; however, the fire quickly engulfed his tent and led to the blaze spreading across the forested island.

Though the man was rescued by authorities and transported to a nearby hospital, two army helicopters and 20 firefighters were needed to douse the flames, which incinerated much of the island’s foliage. Hillesoy is home to nearly 800 people, and luckily it has not been reported that the blaze affected any of the island’s residents.

While setting a blaze of this magnitude is considered illegal in Norway, considering the circumstances officials claim that the man will not be facing any charges.

Norway is famous for its breathtaking fjords and Viking heritage. A hundred years ago at the Oseberg fjord, archaeologists discovered a Viking ship burial containing the bodies of two women. The ship was so well preserved that it could be entirely reconstructed. Now it’s the centerpiece of Oslo’s Viking Ship Museum and one of the country’s most popular attractions.

The Oseberg ship is 21.58 meters (70.8 feet) long and 5.1 meters (16.73 feet) wide. It had a single square sail and fifteen pairs of oars for when the wind wasn’t favorable. Researchers estimate it could achieve a speed of up to 10 knots and was built in the first decades of the ninth century A.D. Its prow and stern are elaborately carved and have graced the covers of many books on the Vikings. Check out the photo gallery for some close-up shots.

The identities of the two women found with the ship are a mystery. One was 60-70 years old when she died, the other about 25-30. Some researchers believe the old woman was a Viking queen or other noblewoman, and the young woman was her slave, sacrificed to accompany her into the afterlife. Others say they were female shamans. One outfit included silk imported all the way from China. Buried with them were household items, a cart and agricultural tools.

%Gallery-157476%The Viking Ship Museum has two other ships. The Gokstad ship is 23.24 meters (76.2 feet) long and 5.20 meters (17.1 feet) wide. It had 16 pairs of oars and a single square sail. Archaeologists estimate up to seventy people could sail in it. Like the Oseberg ship, it was a burial and contained the remains of an elderly man. It’s almost as well preserved as the Oseberg ship and only a little younger, having been made around 890 A.D. Some adventurous Norwegians made a replica of the Gokstad ship and sailed it across the Atlantic to visit the Chicago World’s Fair in 1893.

The Tune Viking ship, dating to about 900 A.D., is also housed at the museum. Although only about half of it survives, it’s still impressive to see.

Besides the ships, the museum houses many of the artifacts found with them, including weapons, clothing, gold and silver, and furniture.

Now curators are worried because they have found the preservative used by the archaeologists who first worked on the Oseberg ship is slowly deteriorating the wood fibers. The race is on to save this precious survival from the early Middle Ages.